The formation of foam is a most undesirable result in most industries as it has a direct and drastic effect upon production efficiency and accordingly the economics of a system or a process.
Foam can be created either chemically or mechanically and is the result of dispersions of gas in the liquid. The gas is the discontinuous phase in the continuous liquid phase. The gas makes up the larger portion of the foam and as a result, the bubbles are separated by a thin liquid film.
Foams can occur in diverse industrial fields. The problems they cause range from an unaesthetic appearance to foams that are actually hazardous. Foam problems are common in paper manufacturing, textile dyeing, phosphoric acid processes, photographic applications, fermentation, polymerization and distillation and oil refining. If not controlled, foam can decrease equipment capacity by occupying space designed for fluids or gases. This increases processing time and expense and can cause other system disadvantages.
Crude oil towers and cokers operating at high temperatures can produce foam in their hydrocarbon products which in turn diminishes the efficiency of the tower or coker, degrading the quality of the overhead products such as gasoline and gas oils.
All of the effective anti-foaming agents known in the industry are silicone (dimethyl polysiloxane) based.
One problem with the use of silicone-based defoamers is that they are expensive to use. Another problem that is significant to the oil industry is that using silicone-based defoamers poison downstream catalysts with silicon carryover and residues.
With the foregoing in mind, the present inventor embarked upon a comprehensive study in an attempt to obtain a foam controller that does not possess the limitations of silicone-based foam controllers.
Accordingly, it is an object of the present invention to provide a method of foam control of hydrocarbon fluids at high temperatures by the use of polyisobutylene compounds.
Further, it is an object of the present invention to control foam in a less expensive manner than silicone-based controllers.
Further still, it is an object of the present invention to use foam controllers that will not poison downstream catalysts in a hydrocarbon distillation system.
Other objects of the present invention will become apparent from the detailed description given herein.